Cancer is a leading cause of death in the United States and many foreign countries. A recent survey by the National Cancer Institute estimates that nearly twelve million Americans have been diagnosed with cancer. Some of the most frequently encountered types of cancer include breast cancer, prostate cancer, skin cancer, colon cancer, rectal cancer, and bladder cancer. Other cancers afflicting a significant number of patients include ovarian cancer, leukemias, brain cancer, lymphomas, uterine cancer, and head and neck cancer.
Current treatment options for cancer typically involve surgery, radiation treatment, and/or chemotherapy. Surgery involves physically removing cancerous tissue. Although surgery is sometimes effective in removing tumors located at certain sites, for example, in the breast, colon, and skin, it cannot be used to treat all types of cancer, such as those located in the backbone or disseminated neoplastic conditions such as leukemia. Radiation therapy involves exposing the patient to ionizing radiation in order to damage the DNA of cancerous cells. Chemotherapy involves administering a chemotherapeutic agent that disrupts cell replication or cell metabolism. Chemotherapy is often used to treat leukemia, breast cancer, lung cancer, and testicular cancer.
Despite the efforts devoted to developing treatments for cancer, current therapeutic options are inadequate because current treatment options frequently have severe side effects and/or are not effective in treating certain types of cancers. For example, the anti-cancer agent 5-fluorouracil has been used to treat various carcinomas, sarcomas, skin cancer, and breast cancer, but this anti-cancer agent causes adverse side effects such as nausea, alopecia, diarrhea, stomatitis, leukocytic thrombocytopenia, and anorexia. The anti-cancer agent cisplatin has been used to treat testicular, ovarian, bladder, head and neck, and esophageal cancer, but this anti-cancer agent has been shown to cause nausea, vomiting, anemia, and reduced white blood cell counts.
Accordingly, the need exists for new therapeutic agents that provide improved efficacy and/or reduced side effects for treating cancer. The present invention addresses this need and provides other related advantages.